The disclosure pertains to an invaginating inflatable balloon catheter and methods of using the catheter. The catheter of the disclosure includes an outer tubular body, an inner tubular body, and an inflatable balloon attached to the tubular bodies such that the balloon is adapted to be inflated within a valve or other tissue to be dilated. During use, the dilating balloon is slowly deflated as aspiration is applied to the inner tubular body and the inflatable balloon is withdrawn into the outer tubular body by proximal motion of the inner tubular body.
